1. The Contractor shall provide a positron emission tomography (PET) scanning system as a flexible, integrated package consisting of all of the components required for acquisition and processing of PET data, including a scanner gantry with detectors and shielding, a patient bed, electronics, front-end computer system, host computer system, display hardware, processing hardware, complete software for acquisition, reconstruction, display, and processing, and complete documentation. a. The system shall be capable of producing a digital reconstructed cross-sectional image of isotope activity concentration (in nCi/cc) with accurate corrections for the physical factors associated with PET (attenuation, random coincidences, scatter, deadtime, differing detector efficiencies, calibration, etc.). b. The system shall be of state-of-the-art design with high detection efficiency and high spatial resolution and be capable of performing static, dynamic, and gated imaging in both frame and list modes. c. The data acquisition and processing system shall be designed to streamline the use of the scanner for routine scanning protocols to facilitate high throughput. In addition, the system shall provide substantial flexibility and complete documentation to allow the investigators at NIH to develop and conveniently implement new algorithms for data acquisition and post-processing. 2. The Contractor shall maintain the system in an operational status with twenty-four (24) hour response time during the warranty or maintenance agreement periods.